One of the main problems to be solved is how to install and keep objects in position in the tyre during sometimes very long periods, which may even be the entire service life of the tyre, with no deterioration in the physical and functional integrity of the tyre and of these objects in what is a highly stressful environment, whether the vehicle to which the equipped tyre is fitted is travelling or at rest.
To avoid having to install an electronic circuit during the manufacture of the tyre and thus subject it to the stresses associated with the shaping of the green tyre and its curing, the proposal has already been made, in document EP 1 070 580 for example, to install on the inner wall of the casing prior to curing an adhesive strip protected by a film of nonstick material. After curing, this film is removed and one face of the package of an electronic circuit is attached to the exposed adhesive strip. The strip allows the package to be at a distance from the wall of the tyre and its flexibility means that it can withstand shear forces during the deformation of the tyre in operation.
Document WO 03/070496 provides another approach in which the inside wall of the tyre is covered before curing with a strip of material whose surface is provided with loops, forming one piece of a touch-close fastener of the hook-and-loop type. The other piece of this fastener is provided with hooks which are capable of engaging in the loops of the first piece when the two pieces are brought together, after the tyre is cured and before it is fitted to a wheel rim. The object to be installed inside the tyre cavity is attached to the non-hook face of this second piece. In a variant of the aforementioned document, the object may be sandwiched between the faces covered with loops and hooks of these two pieces in order to keep it in the selected position on the inside wall. This arrangement, which uses a technique that has long been known for the removable attachment of an object to a tyre, for example from U.S. Pat. No. 3,260,294, has the advantage that the object can be removed at any time when the tyre is taken off the wheel, either to replace it or to reuse it at the end of the tyre's life, or to use certain data relating to it.
However, both the above solutions have the drawback that the first piece of the adhesive or touch-close fastener, integrated into the wall of the tyre during manufacture, by definition hinders the deformation of this wall when subjected to the stresses which it experiences in two cases. The first case is the manufacture of the tyre, particularly when its manufacture involves one or more steps requiring shaping of the casing. The second case is when the tyre is rolling in use, because of course the wall of the casing deforms cyclically with each revolution of the wheel. Furthermore, it is subjected to sometimes substantial deformations as it absorbs all the loads and shocks consequent upon the movement of the wheel over uneven road surfaces, sometimes strewn with obstacles such as potholes, stones, kerbs and so forth.